Arrangement for transfer of a trolley between suspended rails and suspended rail system comprising such an arrangement

ABSTRACT

An arrangement for safe transition of a trolley between a first and a second suspended rail when they are in an end-to-end position with each other, and for safe operation of the trolley when the rails are in un-aligned positions relative each other. The arrangement comprises a liftable first stop member, a liftable second stop member and two pairs of engaging members. 
     The liftable stop members are adapted to block the trolley from accidentally leaving the rails when the rails are in the un-aligned positions, and to unblock the rails when the rails are in the end-to-end position. The engaging members of the pairs of engaging members are arranged to engage with each other when the rails are in the end-to-end position to lift the stop members, thereby unblocking the rails in order to allow a transition between the rails.

TECHNICAL FIELD OF THE INVENTION

The invention relates to the field of suspended rail systems for patientlifts. In particular, the invention relates to a system for allowingsafe transfer of a patient lift trolley between two suspended rails.

TECHNICAL BACKGROUND

Patient lifts which ride on suspended rail systems are commonly used asan aid for lifting, lowering and moving persons who need suchassistance, for example patients, elderly or disabled persons. Thepatient lift is usually coupled to a trolley which rides in a rail ofthe suspended rail system. Such suspended rail systems may compriseprimary rails which are non-movable, e.g. attached to the ceiling, andone or more secondary rails which are suspended from the primary railsand movable relative these. There may arise a need to transfer thepatient lift from one secondary rail to another, or between a secondaryrail and a fixed rail, or between any two rails. This type of transfermay be achieved by positioning the two rails end-to-end and thereafterslide the trolley from one rail to the other. During normal operationhowever, it is desirable for the rails to have stop means to prevent thepatient lift trolley from accidentally leaving the rail. To avoidtime-consuming manual removal of the stop means during a transfersituation, there has been proposed mechanisms for automaticallyreleasing the stop means to allow a transfer.

One such mechanism, called the “Transition gate”, is provided by PrismMedical Ltd. The “Transition gate” comprises rod-shaped stop memberswhich extend into the rails in the vicinity of the ends thereof. Thestop members are movable at a right angle relative the length directionof the rails to be able to either block or allow movement of a trolleythrough the rail. A wheel member is coupled to each stop member at aright angle. The wheels are arranged to interact with guides such thatthe stop members are lifted. Transfer of the patient lift trolleybetween two rails is possible only at certain positions where a guide isattached to a primary rail. At this position, the wheel attached to thestop member of a first rail engages with the guide which is attached tothe primary rail, and the wheel attached to the stop member of thesecond rail engages with a guide being attached to the first rail.Thereby both stop members are lifted and transfer is possible. Oneproblem with such a mechanism may be that both secondary rails need tobe moved to the predetermined position where a guide is attached to aprimary rail in order to make a transfer possible. Another problem isthat the trolley may accidentally leave one of the rails, therebycausing an accident, because a stop member may be lifted without havinganother rail positioned end-to-end, e.g. when a rail is positioned suchthat its stop member wheel engages with a guide which is attached to aprimary rail.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a time-efficient andsafe arrangement for allowing transition of a trolley between a firstand a second suspended rail, and for preventing the trolley fromaccidentally leaving the rails, and at the same time providing such anarrangement with a simple and cost-effective construction. A furtherobject of the present invention is to provide a suspended rail systemcomprising such an arrangement.

These and other objects of the present invention are achieved by meansof an arrangement and a suspended rail system having the featuresdefined in the independent claims. Embodiments of the present inventionare characterized in the dependent claims.

According to a first aspect of the invention, there is provided anarrangement for safe transition of a trolley between a first and asecond suspended rail when they are in an end-to-end position with eachother, and for safe operation of the trolley when the rails are inun-aligned positions relative each other. The arrangement comprises aliftable or movable first stop member, a liftable or movable second stopmember, and two pairs of engaging or actuating members.

The liftable first stop member is adapted to block the trolley fromaccidentally leaving the first rail when the rails are in the un-alignedpositions, and to unblock the first rail when the rails are in theend-to-end position. The liftable second stop member is adapted to blockthe trolley from accidentally leaving the second rail when the rails arein the un-aligned positions, and to unblock the second rail when therails are in the end-to-end position. One pair of engaging members havea first engaging member adapted to be attached to the first rail and asecond engaging member attached to the second stop member. One pair ofengaging members have a third engaging member adapted to be attached tothe second rail and a fourth engaging member attached to the first stopmember. The engaging members of the pairs of engaging members arearranged to engage with each other when the rails are in the end-to-endposition to lift the stop members, thereby unblocking the rails in orderto allow a transition between the rails.

According to a second aspect of the invention, there is provided asuspended rail system comprising a first suspended rail, a secondsuspended rail and an arrangement according to the first aspect of theinvention.

The invention is based on the insight that safe transition of a trolleybetween a first and a second suspended rail may be achieved by mutualengagement between pairs of engaging members, where one of the engagingmembers is attached to one of the rails, and the other is attached to astop member of the other rail, to allow the stop members to be releasedor lifted when the rails are at arbitrary absolute positions given thatthe rails are positioned end-to-end. The invention is furthermore basedon the insight that by using such a mutual engagement between pairs ofengaging members, the stop members may be released or lifted when, andonly when, the rails are positioned end-to-end.

In other words, according to the first aspect of the invention, anarrangement is provided for allowing a transition, transfer or move of atrolley or patient lift trolley between a first and a second suspendedrail or track when the rails or tracks are mutually aligned, and forpreventing the trolley or patient lift trolley from accidentally leavingthe rails or tracks when they are not mutually aligned. Put differently,there is provided an arrangement for enabling a trolley or patient lifttrolley to be transferred or moved between a first and a secondsuspended rail or track when one end of the first suspended rail ortrack is positioned facing one end of the second suspended rail ortrack, and for blocking a trolley or patient lift trolley from leavingthe rails through the one end of the first suspended rail or trackand/or through the one end of the second suspended rail or track whenthe one end of the first suspended rail or track is not positionedfacing the one end of the second suspended rail or track.

The arrangement comprises a liftable or movable first stop member, aliftable or movable second stop member, a first pair of engaging oractuating members and a second pair of engaging or actuating members.The liftable or movable first stop member is adapted to partially blockthe one end of the first rail or track or extend into the first rail ortrack when the rails or tracks are un-aligned or not mutually aligned orwhen the one end of the first suspended rail or track is not facing theone end of the second suspended rail or track. Thereby the trolley orpatient lift trolley is blocked or prevented from leaving the first railor track. The liftable or movable first stop member is furthermoreadapted to unblock the first rail or track when the rails are mutuallyaligned or when the one end of the first suspended rail or track ispositioned facing the one end of the second suspended rail or track. Inother words, the first stop member is movable between a blockingposition and a non-blocking position, depending on if the rails ortracks are positioned end-to-end or not.

The liftable or movable second stop member is adapted to partially blockthe one end of the second rail or track or extend into the second railor track when the rails or tracks are un-aligned or not mutually alignedor when the one end of the first suspended rail or track is not facingthe one end of the second suspended rail or track. Thereby the trolleyor patient lift trolley is blocked or prevented from leaving the secondrail or track. The liftable or movable second stop member is furthermoreadapted to unblock the second rail or track when the rails are mutuallyaligned or when the one end of the first suspended rail or track ispositioned facing the one end of the second suspended rail or track. Inother words, the second stop member is movable between a blockingposition and a non-blocking position, depending on if the rails ortracks are positioned end-to-end or not.

The first pair of engaging or actuating members comprises a firstengaging or actuating member adapted to be attached or coupled to thefirst rail or track and a second engaging or actuating member attachedor coupled to the second stop member. The second pair of engaging oractuating members comprises a third engaging or actuating member adaptedto be attached or coupled to the second rail or track and a fourthengaging or actuating member attached or coupled to the first stopmember. The first engaging or actuating member is arranged to co-operateor engage with the second engaging or actuating member when the railsare mutually aligned or when the one end of the first suspended rail ortrack is positioned facing the one end of the second suspended rail ortrack, thereby unblocking the second rail or track, thereby enabling thetrolley or patient lift trolley to move through the one end of thesecond rail or track in order to allow a transition, transfer or movebetween the rails.

The second engaging or actuating member is arranged to co-operate orengage with the fourth engaging or actuating member when the rails aremutually aligned or when the one end of the first suspended rail ortrack is positioned facing the one end of the second suspended rail ortrack, thereby unblocking the first rail or track, thereby enabling thetrolley or patient lift trolley to move through the one end of thesecond rail or track in order to allow a transition, transfer or movebetween the rails or tracks.

It is understood that the stop members are lifted when the pairs ofengaging members engage with each other, and otherwise remain innon-lifted or blocking positions by gravitational force.

In an embodiment of the invention according to the first and/or secondaspects, the first and third engaging member each has a guide, and thesecond and fourth engaging members each has a protruding portion adaptedto run in respective guide. Each guide has at least one rising portionin order to elevate the protruding portion to lift the stop members. Inother words, the protruding portions of the second and fourth engagingmembers are adapted to slide, run or mate with the guides of the firstand third engaging members, respectively. Because each guide has atleast one rising portion, the protruding portions and the theretoattached stop members are elevated or lifted when the pairs of engagingmembers engage or interact with each other.

In another embodiment of the invention according to the first and/orsecond aspects, each guide may furthermore have a falling portion. Thefalling portion may be symmetric with the rising portion. Thereby, thetrolley is elevated and lowered in the same manner independent of thedirection of relative movement between the first and second rail, i.e.independent of from which side of the engaging member the protrudingportion enters the guide.

In another embodiment of the invention according to the first and/orsecond aspects, the protruding portions of the second and fourthengaging members may be arranged facing each other. The rising portionof the first engaging member may have a different rise than that of thethird engaging member. This is advantageous because collision orinterference between the protruding portions of the second and fourthengaging members may be avoided due to their different verticalpositions because of the different rise of the rising portions.

In yet another embodiment of the invention according to the first and/orsecond aspects, the guide of the first engaging member and the guide ofthe third engaging member may be vertically offset relative each otherwhen the first and third engaging members are attached to the first andsecond rails, respectively. The vertical offset may be achieved byattaching the identical first and third engaging members in a verticallyoffset manner to the first and second rails, respectively.Alternatively, the first engaging member may have a guide which isarranged at a vertical position in the first engaging member which isoffset compared to the vertical position of the guide of the thirdengaging member. Having such an offset is advantageous because collisionor interference between the protruding portions may be avoided.

In yet another embodiment of the invention according to the first and/orsecond aspects, the second and fourth engaging member each has a guide,and the first and third engaging members each have a protruding portionadapted to run in respective guide. Each guide has at least one fallingportion in order to elevate the second and fourth engaging members. Inother words, the first and third engaging members, which are adapted tobe attached to the first and second rails, respectively, each have aprotruding portion which consequently is non-movable relative the rails.The second and fourth engaging members, who are attached to the firstand second stop members, respectively, each has a guide with at leastone falling portion. When the protruding portions enter the fallingportions of the corresponding guides, the second and fourth engagingmembers are elevated or lifted. Thereby, the thereto attached stopmembers are also elevated or lifted.

In yet another embodiment of the invention according to the first and/orsecond aspects, the first and the third engaging members may bevertically offset relative each other. Having such an offset isadvantageous because collision or interference between the protrudingportions may be avoided.

In yet another embodiment of the invention according to the first and/orsecond aspects, the protruding portion is a wheel portion. Thereby, lowfriction may be achieved when the protruding portions run in therespective guides. In other embodiments the protruding portion is a pinportion or a stud portion.

In yet another embodiment of the invention according to the first and/orsecond aspects, the guides may comprise a recess portion at the apex ofthe guide such that the protruding portions are held in position wherethe stop members are at their most elevated position.

In yet another embodiment of the invention according to the first and/orsecond aspects, the guides are grooves or comprise groove portions. Thediameters of the wheel portions of the second and fourth engagingmembers may essentially equal the widths or heights of the grooves orgroove portions of the first and third engaging members or the secondand fourth engaging members, respectively. Thereby, the stop members areessentially fixed in a vertical direction when the wheel portions run inthe grooves or groove portions. The groove or groove portions may beessentially gaussian-shaped. In another embodiment, the groove or grooveportions may comprise a rising portion and a falling portion. The risingand/or the falling portion(s) may have a linear, exponential orlogarithmic rise or fall. The groove or groove portions may furthermorecomprise a plane portion or a convex portion between the rising and thefalling portions.

In yet another embodiment of the invention according to the first and/orsecond aspects, the guides may be cams or cam guides, i.e. guides havingrising and falling surfaces on which the protruding portions are adaptedto run. The cam or cam guide may be essentially gaussian-shaped. Therising and/or the falling surfaces may have linear, exponential orlogarithmic rise or fall. The cam or cam guide may furthermore comprisea plane surface or a convex surface between the rising and the fallingportions.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the present invention will now be describedin more detail, with reference to the appended drawings showingcurrently preferred embodiments of the invention, wherein:

FIG. 1 is an illustration of a system in accordance with an embodimentaccording to the second aspect of the invention where the rails are inun-aligned positions,

FIG. 2 is an illustration of the system in FIG. 1, where the rails arein an end-to-end position,

FIG. 3 is an illustration of the system in FIGS. 1 and 2, where therails are in un-aligned positions,

FIG. 4 is an illustration of a system in accordance with an embodimentaccording to the second aspect of the invention where the rails are inun-aligned positions,

FIG. 5 is an illustration of the system in FIG. 4, where the rails arein an end-to-end position,

FIG. 6 is an illustration of the system in FIGS. 4 and 5, where therails are in un-aligned positions.

DETAILED DESCRIPTION

In the following description, an embodiment of the present invention isdescribed with reference to a suspended rail system having first andsecond rails and an arrangement for safe transition of a trolley betweenthe rails.

FIG. 1 shows a suspended rail system according to an embodiment of theinvention. A first rail 1 and a second rail 2 being arranged in paralleland having rectangular cross-sections are shown. In other embodiments,the rails may have a quadratic or partially curved cross-section. Therails 1, 2 are adapted to allow a trolley to ride therein. The trolleymay be of the type having a mounting bracket attached to its bottomportion. The mounting bracket is adapted to have a hook or holderattached thereto such that a portable patient lift may be suspendedtherefrom. Alternatively, a motor device for elevating or lowering thepatient may be coupled to the mounting bracket directly or via a hook orholder. The rails each have a slit in their bottom surfaces extendingalong the length of the rails such that a trolley having for example aportable patient lift or a motor device coupled thereto may move or ridein the rail. The first rail 1 has an end surface 3, and the second rail2 has an end surface 4. In FIG. 1, the rails are not mutually aligned orin an end-to-end position, i.e. the end surfaces 3, 4 are not facingeach other.

On top of the first rail 1, a first engaging member 5 is attached, andon top of the second rail 2, a third engaging member 6 is attached. Thefirst and second engaging members 5, 6 have T-shaped cross-sections asseen from above, and have plane front surfaces 5 a, 6 a adapted to faceeach other when the rails 1, 2 are arranged in an end-to-end position.The front surfaces 5 a, 6 a are at right angles with the direction ofextension of the rails. The T-shaped cross-section is chosen to ensurestable attachment possibilities to the rails and the shape may be chosenin any appropriate way as realized by the person skilled in the art. Theengaging member 5, 6 each have a groove 5 b, 6 b cut into the frontsurfaces 5 a, 6 a. The grooves 5 b, 6 b have a Gaussian-shaped extensionand start and end on either side of respective engaging members 5, 6.The grooves have a rectangular cross-section with a depth which isapproximately one-third of the width. The groove 6 b has a larger risethan that of the groove 5 b.

The first and second engaging members furthermore each have a verticalgroove 5 c, 6 c cut into the front surfaces 5 a, 6 a. The verticalgrooves 5 c, 6 c are deeper than the Gaussian-shaped grooves 5 b, 6 b,and extend partially along the height of the first and second engagingmembers, leaving a lower portion of the front surfaces 5 a, 6 a un-cut.

A first stop member 7 is arranged to be movable in the vertical groove 5c and through a hole in a top portion of the first rail 1. A second stopmember 8 is arranged to be movable in the vertical groove 6 c andthrough a hole in a top portion of the second rail 2. The stop membersare thus arranged to be moved at an essentially right angle relative therails. The first and second stop members 7, 8 have a length such thatthey extend into the corresponding rails down to approximately 50% ofthe height of the rails when the rails are not arranged end-to-end. Thefirst and second stop members 7, 8 each have cylinder-shaped bodies. Inother embodiments, the stop members may have for example plate-shapedbodies or bodies having a rectangular cross-section. A second engagingmember 9 and a fourth engaging member 10 each comprise a wheel portionattached to a corresponding stop member 7, 8 at right angles via an axleportion. In other embodiments, the second and fourth engaging membersmay comprise a pin or stud portion instead of the wheel portion. Thesecond and fourth engaging members 9, 10 are pointing in oppositedirections, at right angles away from the front surfaces 5 a, 6 a of thefirst and second engaging members. The axle portions are resting againstlower portions of the vertical grooves 5 c, 6 c. The stop members 7, 8will remain in this blocking position by means of gravitational force aslong as the rails are not arranged end-to-end.

FIG. 2 shows the same embodiment of the suspended rail system as inFIG. 1. In FIG. 2, the rails are mutually aligned or in an end-to-endposition, i.e. the end surfaces 3, 4 are facing each other. The wheelportions of the second and fourth engaging portions 9, 10 havepreviously to arriving at the shown position, i.e. the highest positionsin respective grooves 5 b, 6 b, run in the grooves and followed theirrise to the present elevated position. Because the stop members 7, 8 areattached to the second and fourth engaging members, the stop members arealso in elevated positions and do not extend into the rails 1, 2.Thereby, both rails 1, 2 are un-blocked and a transfer or transition ofa trolley from the first to the second rail or vice versa is possible.Because of the different rise of the groove 16 b compared to the groove15 b, the wheels of the second and fourth engaging members are preventedfrom colliding.

FIG. 3 shows the same embodiment of the suspended rail system as inFIGS. 1 and 2. In FIG. 3, the rails are no longer mutually aligned or inan end-to-end position. The end surfaces 3, 4 are partially overlappingor facing each other, but are not sufficiently aligned to allow atransfer or transition. The wheel portions are halfway up the grooves 5b, 6 b. Therefore, the stop members 7, 8 are in a partially elevatedposition, but extend sufficiently into the rails 1, 2 in order to blocka trolley from accidentally leaving either of the rails.

FIG. 4 shows a suspended rail system according to another embodiment ofthe invention. The rails 11, 12 are of the same type described above andas shown in FIGS. 1-3. In FIG. 4, the rails are not mutually aligned orin an end-to-end position, i.e. the end surfaces 13, 14 are not facingeach other. On top of the first rail 11, a first engaging member 15 isattached, and on top of the second rail 12, a third engaging member 16is attached. The first and second engaging members 15, 16 have T-shapedcross-sections as seen from above, and have plane front surfaces 15 a,16 a which are adapted to face each other when the rails 11, 12 arearranged in an end-to-end position. The front surfaces 15 a, 16 a are atright angles with the direction of extension of the rails. The T-shapedcross-section is chosen to ensure stable attachment possibilities to therails and the shape may be chosen in any appropriate way as realized bythe person skilled in the art. The engaging members 15, 16 each have agroove 15 b, 16 b cut into the front surfaces 15 a, 16 a. The grooves 15b, 16 b have a Gaussian-shaped extension and start and end on eitherside of respective engaging members 15, 16. The grooves have arectangular cross-section with a depth which is approximately one-thirdof the width. The groove 16 b has the same shape as the groove 15 b, andthe grooves are vertically offset relative each other. The groove 16 bis thus offset at a higher position compared to the groove 15 b.

The first and second engaging members furthermore each have a verticalgroove 15 c, 16 c cut into the front surfaces 15 a, 16 a. The verticalgrooves 15 c, 16 c are deeper than the Gaussian-shaped grooves 15 b, 16b, and extend partially along the height of the first and secondengaging members, leaving a lower portion of the front surfaces 15 a, 16a un-cut.

A first stop member 17 is arranged to be movable in the vertical groove15 c and through a hole in a top portion of the first rail 11. A secondstop member 18 is arranged to be movable in the vertical groove 16 c andthrough a hole in a top portion of the second rail 12. The stop membersare thus arranged to be moved at an essentially right angle relative therails. The first and second stop members 17, 18 have a length such thatthey extend into the corresponding rails down to approximately 50% ofthe height of the rails when the rails are not arranged end-to-end. Thefirst and second stop members 17, 18 each have cylinder-shaped bodies. Asecond engaging member 19 and a fourth engaging member 110 each comprisea wheel portion attached to one of the stop members 17, 18 at rightangles via axle portions. The second and fourth engaging members 19, 110are pointing in opposite directions, away from the front surfaces 15 a,16 a of the first and second engaging members. The axle portions areresting against lower portions of the vertical grooves 15 c, 16 c. Thestop members 17, 18 will remain in this blocking position by means ofgravitational force as long as the rails are not arranged end-to-end.

FIG. 5 shows the same embodiment of the suspended rail system as in FIG.4. In FIG. 5, the rails are mutually aligned or in an end-to-endposition, i.e. the end surfaces 13, 14 are facing each other. The wheelportions of the second and fourth engaging portions 19, 110 havepreviously to arriving at the shown position, i.e. the highest positionsin respective grooves 15 b, 16 b, run in the grooves and followed theirrise to the present elevated position. Because the stop members 17, 18are attached to the second and fourth engaging members, the stop membersare also in elevated positions and do not extend into the rails 11, 12.Thereby, both rails 11, 12 are un-blocked and a transfer or transitionof a trolley from the first to the second rail or vice versa ispossible. Because of the vertical offset between the grooves 15 b, 16 b,the wheels of the second and fourth engaging members are prevented fromcolliding.

FIG. 6 shows the same embodiment of the suspended rail system as inFIGS. 4 and 5. In FIG. 6, the rails are no longer mutually aligned or inan end-to-end position. The end surfaces 13, 14 are partiallyoverlapping or facing each other, but are not sufficiently aligned toallow a transfer or transition. The wheel portions are halfway up thegrooves 15 b, 16 b. Therefore, the stop members 17, 18 are in apartially elevated position, but extend sufficiently into the rails 11,12 in order to block a trolley from accidentally leaving either of therails.

Although exemplary embodiments of the present invention has been shownand described, it will be apparent to the person skilled in the art thata number of changes and modifications, or alterations of the inventionas described herein may be made. In particular, the first and thirdengaging members may switch positions with the second and fourthengaging members, i.e. such that the second and fourth engaging membersare attached to the first and second rail, respectively, and the firstand third engaging members are attached to the liftable stop members andmovable therewith. The person skilled in the art furthermore realizesthat the exact shape of the engaging members is not limited to theembodiments shown above. Thus, it is to be understood that the abovedescription of the invention and the accompanying drawing is to beregarded as a non-limiting example thereof and that the scope of theinvention is defined in the appended patent claims.

1. An arrangement for safe transition of a trolley between a first and asecond suspended rail when they are in an end-to-end position with eachother, and for safe operation of said trolley when said rails are inun-aligned positions relative each other, said arrangement comprising: aliftable first stop member adapted to block said trolley fromaccidentally leaving said first rail when said rails are in saidun-aligned positions, and to unblock said first rail when said rails arein said end-to-end position; a liftable second stop member adapted toblock said trolley from accidentally leaving said second rail when saidrails are in said un-aligned positions, and to unblock said second railwhen said rails are in said end-to-end position; one pair of engagingmembers having a first engaging member adapted to be attached to saidfirst rail and a second engaging member attached to said second stopmember; one pair of engaging members having a third engaging memberadapted to be attached to said second rail and a fourth engaging memberattached to said first stop member; wherein said engaging members ofsaid pairs of engaging members are arranged to engage with each otherwhen said rails are in said end-to-end position to lift said stopmembers, thereby unblocking said rails in order to allow a transitionbetween said rails.
 2. The arrangement according to claim 1, whereinsaid first and third engaging member each has a guide, and wherein saidsecond and fourth engaging members each comprise a protruding portionadapted to run in respective guide, and wherein said guides eachcomprise at least one rising portion in order to elevate said protrudingportion to lift said stop members.
 3. The arrangement according to claim2, wherein said rising portion of said first engaging member has a risedifferent than that of said third engaging member.
 4. The arrangementaccording to claim 1, wherein said second and fourth engaging membereach has a guide, and wherein said first and third engaging members eachcomprise a protruding portion adapted to run in respective guide, andwherein said guides each comprise at least one falling portion in orderto elevate the second and fourth engaging members lift said stopmembers.
 5. The arrangement according to claim 2, wherein saidprotruding portion is a wheel portion or a pin portion.
 6. Thearrangement according to claim 2, wherein said guides are grooves.
 7. Asuspended rail system comprising a first suspended rail, a secondsuspended rail and an arrangement according to claim 1, wherein saidfirst engaging member is attached to said first rail, and said thirdengaging member is attached to said second rail.
 8. The system accordingto claim 7, wherein said first and third engaging member each has aguide, wherein said second and fourth engaging members each comprise aprotruding portion adapted to run in respective guide, wherein saidguides each comprise at least one rising portion in order to elevatesaid protruding portion to lift said stop members, and wherein saidguide of said first engaging member and said guide of said thirdengaging member are vertically offset relative each other.
 9. The systemaccording to claim 7, wherein said second and fourth engaging membereach has a guide, wherein said first and third engaging members eachcomprise a protruding portion adapted to run in respective guide,wherein said guides each comprise at least one falling portion in orderto elevate the second and fourth engaging members lift said stopmembers, and wherein said first engaging member and said third engagingmember are offset in a vertical direction relative each other.
 10. Thesystem according to claim 8, wherein said protruding portions are facingeach other.
 11. The system according to claim 8, wherein said stopmembers are liftable at essentially right angles relative said rails.12. The system according to claim 8, wherein said stop members extendinto said rails through top portions of said rails.
 13. The arrangementaccording to claim 3, wherein said protruding portion is a wheel portionor a pin portion.
 14. The arrangement according to claim 4, wherein saidprotruding portion is a wheel portion or a pin portion.
 15. Thearrangement according to claim 3, wherein said guides are grooves. 16.The arrangement according to claim 4, wherein said guides are grooves.17. The arrangement according to claim 5, wherein said guides aregrooves.
 18. A suspended rail system comprising a first suspended rail,a second suspended rail and an arrangement according to claim 2, whereinsaid first engaging member is attached to said first rail, and saidthird engaging member is attached to said second rail.
 19. A suspendedrail system comprising a first suspended rail, a second suspended railand an arrangement according to claim 3, wherein said first engagingmember is attached to said first rail, and said third engaging member isattached to said second rail.
 20. A suspended rail system comprising afirst suspended rail, a second suspended rail and an arrangementaccording to claim 4, wherein said first engaging member is attached tosaid first rail, and said third engaging member is attached to saidsecond rail.